Combination log chipping and sawing apparatus

ABSTRACT

Apparatus for simultaneously removing slab material and cutting a board from a log in a lumber mill. As each log is moved on a sawmill carriage towards a head saw, slab or side material thereof is removed by a chipper head in the form of chips, thereby providing the log with a face parallel to the cutting plane of the saw. The speed of rotation of the chipper head is changed instantly when the carriage speed changes in order to produce chips having predetermined fiber length regardless of the usual variations in carriage speed.

United States Patent [72] Inventor Peter J. Neild North Vancouver, British Columbia, Canada [21] App 1.No. 12,687

[22] Filed Feb. 19, 1970 [45] Patented Oct. 12, 1971 [7 3] Assignee MacMillan Bloedel Limited Vancouver, British Columbia, Canada Continuation-impart of application Ser. No. 688,497, Dec. 6, 1967, now abandoned.

[54] COMBINATION LOG CHIPPING AND SAWING APPARATUS 12 Claims, 8 Drawing Figs.

[52] US. Cl .4 144/39, 143/25,l43/26, 144/1 R, 144/3 P, 144/312, 144/326 R [51] Int. Cl B27b 25/00 [50] Field of Search 144/312, 326 R, l R, 3 P, 39; 143/25, 26

[56] References Cited 1 UNITED STATES PATENTS 3,552,457 l/1971 Bos 144/3 Primary ExaminerGerald A. Dost Att0rneyFetherst0nhaugh & Co.

ABSTRACT: Apparatus for simultaneously removing slab material and cutting a board from a log in a lumber mill. As each log is moved on a sawmill carriage towards a head saw, slab or side material thereof is removed by a chipper head in the form of chips, thereby providing the log with a face parallel to the cutting plane of the saw. The speed of rotation of the chipper head is changed instantly when the carriage speed changes in order to produce chips having predetermined fiber length regardless of the usual variations in carriage speed.

PATENTEUncH 2197: 1612.119 sum 1 0F 4 Q PATENTEDDBHZ'ISYI 3512.119-

sum 2 or 4 INVC N101 PETER J. NEILD PATENTEU nm 1 2 l9?! 3,612,119

sum 3 or 4 PETER J. NEILD INDUC TOR MOTOR D. C. SHUNT GENERATOR AMPLIDYNE 9s EXCITER -99 0. c. snur Moran INVNTO R PETER J. NEILD Anon COMBINATION LOG CIIIPPING AND SAWING APPARATUS This is a continuation-in-part of application Ser. No. 688,497, filed Dec. 6, 1967 and now abandoned.

BACKGROUND OF THE INVENTION This invention relates to combination apparatus for simultaneously converting outer portions of logs to chips of predetermined fiber length while cutting boards of various thicknesses therefrom.

Under standard practice, when a log is to be cut into boards, it is placed on a sawmill carriage so as to extend longitudinally thereof with reference to the direction of movement of the carriage, and is clamped thereon with a portion of the log projecting laterally from the carriage into the cutting plane of a head saw. The sawyer controls the thickness of wood to be cut from the log each time the latter is moved past the saw by shifting the log laterally on the carriage. As the log has a curved outer surface, the sawyer decides what thickness of wood is to be removed in order to form a plane surface for the first board to be cut from the log. It is standard practice to move the log past the saw to form flat faces thereon, and each removed piece of wood is usually called a slab". These slabs have to be conveyed away from the head saw apparatus and either burned or converted into chips to be used in the pulp industry. In some cases, a thick slab is cut from the side of the log and then conveyed to a resaw which in turn cuts this slab into a thin slab and a board. The thin slab is burned or chipped. Furthermore, when a slab is cut from a log, a man, positioned near the headsaw, for this purpose, must make sure that the slab falls with its sawn surface down against the conveying rolls, and not the curved outer surface thereof, in order to ensure that the said rolls .convey the slab away. These operations necessitate additional handling of the slabs, machinery for converting them into chips, and the use .of floorspace in the mill. In addition, the chipping of refuse wood in a typical chipping plant is relatively uncontrolled since the wood is conveyed in a somewhat random orientation to the chipper knives and is not firmly held during the chipping operation. As a result, the lengths of the fibers of the chips are not consistent, and such chips are considered low quality. Furthermore, the sawdust resulting from the sawing off of the slabs is waste product and has to be removed.

Logs are slabbed in order to square them to produce cants or squared timbers. The number of slabs removed depends upon the diameter and properties of the log and other well-known factors. For the sake of convenience, reference herein will be made mainly to the cutting of one slab only, but it is to be understood that any given log can have more than one slab removed by the apparatus constituting the present invention.

SUMMARY OF THE INVENTION Apparatus according to this invention comprises the combination of a head saw, a carriage mounted for reciprocal movement so as to be able to move a longitudinally extending log firmly clamped thereon past the saw to enable the latter to cut boards from the log, and a chipper head unit mounted on the same side of the carriage as the saw and movable towards and away from the carriage. The chipper head of the unit is adapted to cut chips from the side of the log as the latter is moved towards the head saw. Means is provided for selectively shifting the chipper head to various positions relative to the plane of the head saw. Means are included for sensing the speed of movement of the carriage and the log thereon, and for controlling the speed of rotation of the chipper head in accordance with the log speed. This apparatus has several advantages over the prior art. When the carriage with a log clamped thereon is moved past the chipper unit, chips alone can be cut from the log, or the chips can be cut at the same time as a board is being cut from the log by the head saw, or a boardalone can be cut from the log. The fiber length of the chips can be controlled very accurately since the log is firmly held on the carriage when the chipper head is cutting the chips. In addition, the length of the chip fibers can readily be adjusted and is maintained constant by controlling the speed of movement of the carriage and the speed of rotation of the chipper head in accordance with the carriage speed. Boards of different thicknesses can be cut while the chips are being produced during movement of the carriage past the head saw, and any desired number of additional boards can be cut from the log without any interference by the chipper head. The normal sawdust waste which exists when slabs are cut is eliminated, as are the time, effort, men .and equipment necessary to handle slabs, reshw them and to convert slabs into chips which, in the past, have been of an inferior grade. The chips produced by this apparatus are of a high grade since they are accurately and constantly produced with predetermined fiber lengths. A further advantage of this apparatus is that the simultaneous chipping and sawing action results in increased production at the head saw, i.e. more cuts made per unit of time.

BRIEF DESCRIPTION OF THE'DRA-WINGS FIG. 1 is a diagrammatic perspective view .of log chipping and sawing apparatusin accordance withthis invention,

FIG. 2 is a plan view of the apparatus, .with most of the sawmill carriage omitted,

FIG. 3 is a side elevation of the apparatus as shown in FIG. 2, the carriage being seen in end elevation,

FIG. 4 is a sectional view taken on the line 4-4 of FIG. 3,

FIG. 5 is an enlarged diagrammatic side elevation of one form of chipper head used in the chipper unit,

FIG. 6 is an end elevation of the chipper head of FIG. 5,

FIG. 7 is an enlarged isometric view of a chipping blade of this head, and

FIG. 8 is a diagram illustrating a preferred form of electrical sensing means and control means for instantly varying the speed of the chipper head with variations in the carriage speed.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to the drawings, 10 is an example of combination log chipping and sawing apparatus in accordance with the present invention. This apparatus includes a carriage 12 mounted to travel back and forth on rails 13; a head saw 14 which, in this example, is a bandsaw mounted near and to one side of the rails; and a chipper unit 16 which is mounted on the same side of the rails as the head saw ahead of the latter with respect to the movement of the carriage when a log is moved past said unit in the direction of the saw.

Carriage 12 may be any suitable sawmill carriage which is normally used with a head saw alone. The illustrated carriage includes a base 20 supported by wheels 21 which ride on the rails 13. A plurality of supports or knees 23 are mounted on base 20 and extend transversely thereof. One end 24 of each knee terminates adjacent side 25 of the carriage base, while the opposite end 27 of the knee projects beyond the opposite side 28 of the carriage. A block 30 is slidably mounted on and projects upwardly from each knee 23. Blocks 30 are adjustable relative to each other in order to support and align a log thereon relative to the carriage, and are simultaneously moved transversely of the carriage by standard equipment, not shown. Each block has a lower dog 32 and an upper dog 33 which are retractable, see FIGS. 1 and 3, and are adapted to grip a log 35 resting on knees 23 and extending longitudinally of the carriage. Standard mechanism, not shown, moves dogs 32 and 33 into and out of log-gripping position in the usual manner. These dogs and the blocks 30 are controlled by the sawyer, usually at a station off the carriage, such a station being illustrated at 37 in FIG. 1.

Carriage I2 is reciprocated on rails 13 by any known type of apparatus for this purpose. In this example, cables 39 and 40 are wound in opposite directions on a drum 41. These cables extend away from the drum in opposite directions, and extend around suitable sheaves to opposite ends 43 and 44 of carriage 12 to which said cables are connected. A suitable source of power, such as an electric motor, and gear drive for drum 41 are mounted in a housing 45.

The sawyer controls the movement of carriage 12, the shifting of logs 35 and the movement of dogs 32 and 33 through standard controls, not shown, in the usual manner. When a log 35 is placed upon knees 23 of the carriage and against blocks 30, dogs 32 and 33 are moved to grip the log near the top and bottom surfaces thereof. Then blocks 30 are moved to shift the side portion of the log outwardly of side 28 of the carriage. After each pass of the log past head saw 14, blocks 30 may be shifted outwardly a predetermined distance so that a board of a desired thickness will be cut off the log the next time the carriage passes the saw.

As previously stated, saw 14 is a standard head saw. The blade of the saw lies in a plane extending parallel to the path movement of carriage 12 and to one side of the latter. The thickness of each board cut off the log as the carriage moves past the saw depends upon the amount of the side of the log projecting outwardly from the carriage across the plane of the saw blade.

Chipper unit 16 includes a base 50 slidably mounted on rails 52 for movement towards and away from the path of movement of carriage 12 along rails 13. The movement of unit 16 is normal to the plane of head saw 14. Base 50 is provided with slides 53 which retain the base on rails 52 while permitting relative movement therebetween. A heavy duty, variablespeed electric motor 55 is mounted on base 50, said motor being something of the order of 250 h.p. at speeds variable in the range of 400 to 1,200 r.p.m. The power shaft 56 of this motor is connected by coupling 57 to a shaft 58 journaled in suitable bearings 59 mounted on base 50. A chipper head 60 is mounted on the outer end of shaft 58 and beyond the adjacent end of base 50. If desired, a suitable fan 62 driven by an electric motor 63 may be mounted on base 50 and arranged to cool motor 55.

Suitable means is provided for selectively moving chipper unit 16 towards and away from the plane of head saw 14. A standard mechanohydraulic setworks 66 is shown for this purpose. The setworks 66 is mounted on transverse bars 68 which extend across rails 52 and are normally fixed secured thereto. The setworks includes a hydraulic cylinder 70 with a piston rod 71 projecting from an end thereof and connected at 72 to the end of base 50 remote from the head saw plane.

Setworks 66 can be operated by the sawyer to shift chipper unit 16 towards and away from the plane of the head saw. The adjustments are such that the cutters of head 60 can be shifted to various positions from the side of the saw plane remote from the chipper unit to a position well clear of carriage l2 and any log thereon. Chipper head 60 is shown in FIG. 3 in a position to cut away as chips the slab portion or area of log 35 as carriage 12 moves past said head. The head is also shown at position 600 retracted well clear of the carriage, and in position 60b where repairs and knife changes can be made in the chipper unit without danger to the workmen while leaving the carriage and head saw free to operate in the standard manner. Rails 52 are long enough to permit this movement of the chipper unit, and bars 68 are released from the rails so that setworks 66 can slide therealong at this time.

Cutter head 60 may be any suitable type. The illustrated head has a base or body 75 fixedly mounted on the end of shaft 58, see FIGS. 2, 3 and 5. A plurality of substantially L- shaped cutting blades 76 radiate from the surface 77 of body 75. One of these blades is illustrated in FIG. 7. As this cutterhead-and-blade arrangement is known and does not form part of this invention, detailed description is unnecessary. As a log is moved past cutter head 60 in the direction normal to the axis of rotation thereof, blades 76 remove the wood aligned with and approaching them in the form of chips. In the illustrated example, body 75 is hollow, and the chips cut by the blades enter the body through slots 78 adjacent the blades, and fall downwardly into a chute 79 which conveys the chips away from the apparatus. The hollow head or base acts as hood means for directing the chips away from the blades into said chute.

The speed of the motor or driving means of carriage 12 can be regulated to reciprocate the carriage at different speeds. Motor 55 is variable so that the speed of rotation of chopper head 60 can be varied. The speed of the carriage determines the rate of feed of the log to the head saw, and this feed rate should be regulated for best sawing. To produce optimum chip fiber length, one chipping head knife must enter the log for each chip fiber length of log travel. An electrical circuit can sense the log speed and match the chipper head speed therewith to produce optimum length chips. In this way, the chipper head rational speed complies with the log speed.

Power-driven rolls may be positioned along the path of travel of carriage 12 to one side thereof. These rolls are outside saw 12 with respect to the carriage so that when a board is cut off a log mounted on the carriage, it will fall outwardly onto these rolls and be carried away from the apparatus. Rolls 85 are positioned so that they do not interfere with the operation of the chipper unit.

The speed of carriage 12 and consequently the speed of log 35 thereon, is constantly changing. The sawyer controls the speed of movement of the carriage in accordance with the cutting conditions, and in addition, the carriage has to accelerate from a stop at each end of its travel. in order to produce high-grade chips, it is necessary to maintain the fiber length thereof constant, and in order to do this, the speed of rotation of the cutter head must vary instantly with changes in the speed of movement of the carriage. FIG. 8 diagrammatically illustrates very sensitive electrical control means for instantly changing the speed of the cutter head when the speed of the carriage alters.

The chipper motor 55 is preferably a DC shunt motor. In this example, power for motor 55 is obtained from a DC shunt generator 92 driven by an induction motor 93. With fixed field excitation applied to motor 55, the carriage speed is proportional to the applied armature voltage. The armature voltage, supplied by generator 92, is changed by adjusting the genera tor field current. Therefore, the speed of chipper head 60 increases and decreases as the generator field current is increases and decreased.

A suitable type of exciter 96 is used, and this is preferably the well-known amplidyne exciter. Whereas the ratio of output current to excitation current for a conventional exciter may be 25/ 1, this same ratio is 10.000/1 for the amplidyne exciter. An electrical tachometer 98 is mounted so as to measure the speed of carriage 12, and this tachometer is connected by a feedback loop 99 to the amplidyne exciter. With this arrangement, the chipper head drive is controlled by cur rents amounting to only a fraction of an ampere. The tachometer, through the amplidyne, directly controls the excitation of generator 92 which, in turn, controls the armature voltage of motor 55 which changes the speed of the chipper head.

Each time tachometer 98 measures or senses an increase or decrease in carriage speed, the field-forcing action of the amplidyne tends instantly to change the generator voltage so that the chipper head respectively accelerates or decelerates to a speed corresponding to the new carriage speed, thus maintaining a direct relationship between carriage speed and chipper head speed. This allows the chipper head to maintain close tolerance on chip fiber length over a wide range of carriage speeds. The current limit control automatically limits the motor current to a maximum value established for good commutation of the DC generator 92 and the DC motor 55. The maximum value of current determines the maximum acceleration that the carriage can achieve while the chipper head is ac celerating and chipping uniform chip lengths. Through this automatic forcing and current limit action of the amplidyne, a higher acceleration is achieved than can be reached by any other control scheme. At the same time, the current is kept within safe operating limits, thus avoiding damage to the motor and generator. The amplidyne exciter and the heavyduty millotype DC motor 55 allow the drive to maintain very high acceleration torques while closely maintaining chipper head speed to the desired ratio of the carriage speed.

Although the described control means are considered to be the best for this purpose, other controls can be used, but these must be such that the ratio of the speed of the carriage to the speed of rotation of the chipper head can be set, and that these will remain reasonably constant'regardless of the changes in the speed of the carriage during movement thereof.

The operation of apparatus is relatively simple. A whole log 35 is placed on carriage l2 and gripped by lower and upper dogs 32 and 33 in the manner described above. The sawyer can keep chipper unit 16 retracted and move the carriage past saw 14 in the standard manner. However, in order to attain the benefits of the present apparatus, the sawyer will advance the chipper unit and cause blocks 30 to shift log 35 outwardly of the carriage sufficiently to enable a desired thickness or depth of slab material to be removed therefrom and a board of desired thickness simultaneously cut from the log. When the carriage moves towards the head saw, the side of the log first comes into contact with the cutters of chipper head 60, and these remove slab material from the log in the form of chips. The slab material area of the log is indicated at 90 in FIG. 3. As the carriage progresses towards and past 14, a board 92 is cut therefrom. Thus, the slab material and a board are simultaneously removed from the log during a single pass relative to the head saw. If the band of saw 14 has teeth on both side edges thereof, another board may be cut from the log when the carriage is moved in the opposite direction, after the chipping unit has been retracted and the setworks has advanced the log on the carriage. If the band does not have two sets of cutting teeth, the carriage moves back past the blade and the chipper unit without the the log being contacted by either of these. Then the sawyer can shift the log outwardly relative to the carriage a desired amount in order to cut another board from the log. If one or more additional boards are cut from the log, the chipper unit remains retracted clear of the rolls 85 during this time.

The slab material can be removed as chips from the log without simultaneously cutting a board therefrom merely by shifting unit 16 so that head 60 removes the wood up to or across the plane of saw 14.

if the sawyer desired to square the log without cutting any boards therefrom, he can flatten one side of the log by removing the slab material therefrom as chips by means of the chipper head. Then the log is rotated through 90and the new slab area is removed as chips. This operation is repeated twice more until the log is square. This same process may be carried out while simultaneously cutting a board off the log during each slab-material-moving pass. At any time, if the thickness of the slab material is greater than the cutting capability of the chipper head, a second chipping pass can be made, after the setworks has advanced the log on the carriage.

An important feature of this apparatus is that it is operated mainly in accordance with standard practice. The sawyer is used to fitting the logs on the carriage in order to remove slabs therefrom, but with this equipment, he adjusts the amount of log projecting laterally from the carriage and the position of the chipper unit to determine the thickness of the slab material to be removed. He simultaneously cuts a board from the log by positioning the log for this purpose. For example, if he wishes to remove 1 inch of slab material and simultaneously cut a 2 inch board, he would operate the setworks to shift block 30 to move the log outwardly for a 3 inch cut by the head saw. He then shifts chipper unit 16 so as to remove slab material to the depth of 1 inch. The required depth of chips and the board are removed as the carriage passes the chipper unit and the head saw.

As the log is moved longitudinally past chipper head 60 the chips are cut out of the log with the desired fiber length. The fiber length of the chip is determined and may be adjusted by the speed of rotation of head 60 relative to the speed of movement of carriage 12. As stated above, if chipper unit 16 requires any attention, it can be shifted outwardly completely away from the carriage so that the latter can be operated to cut boards from logs in the standard manner without danger to persons working on the chipper unit.

The quality of the chips for pulp purposes can be accurately controlled by this apparatus, and is maintained on a high plane. One of the reasons for this is that the log from which the chips are cut is firmly held so that the fiber length of the chips can be determined simply by matching the speed of the chipper head rotation to the carriage speed.

lclaim:

1. Apparatus for chipping and sawing logs comprising, in combination, a head saw, a sawmill carriage mounted for movement past the saw, gripping means on the carriage for holding a log extending longitudinally thereof in order that a board can be cut therefrom when the carriage moves past the saw, a chipper unit mounted near the path of travel of the carriage for movement towards and away from said path, a chipper head on the unit on the same side of the carriage as the head saw and positioned and adapted to cut into chips having a predetermined fiber length the side of the log on the carriage as the latter moves in the direction of the saw, means for selectively moving the chipper unit in a direction substantially normal to the plane in which the saw is located to shift the head to various positions relative to said plane, manually operable first control means for controlling the speed of the carriage in accordance with sawing conditions, second control means for regulating the speed of rotation of the cutting head, means for constantly sensing the speed of the carriage and operably connected to said second control means for instantly changing the speed of rotation of the chipper head in accordance with changes in the carriage speed, whereby chips are produced having said predetermined fiber length regardless of carriage speed changes during movement thereof.

2. Apparatus as claimed in claim 1 in which the means for moving the chipper unit and head selectively moves said head anywhere from a position on the same side of the saw plane as the carriage to a position on the opposite side and clear of said plane.

3. Apparatus for chipping and sawing logs comprising, in combination, a head saw, a sawmill carriage mounted for movement past the saw, gripping means on the carriage for holding a log resting on and extending longitudinally of the carriage in order that a board can be cut therefrom when the carriage moves past the saw, said gripping means gripping the log throughout substantially the length thereof and on the side of the log remote from said saw, a chipper unit mounted near the path of travel of the carriage for movement towards and away from said path, a chipper head on the unit on the same side of the carriage as the head saw and positioned and adapted to cut into chips having a predetermined fiber length the side of the log on the carriage as the latter moves in the direction of the saw, control means for causing the carriage to reciprocate past the head saw and the chipper head, said control means including means for stopping and starting the carriage at the end of each run and a first varying means for varying the speed of the carriage during each run, second varying means for varying the speed of rotation of the chipper head, means for constantly sensing the speed of the carriage operatively connected to said second varying means instantly to change the speed of rotation of the chipper head in accordance with changes in the carriage speed during movement thereof, and means for selectively moving the chipper unit in a direction substantially normal to the plane in which the same is located to shift the head to various positions relative to said plane, wherein said first and second varying means are coordinated with each other through the said sensing means to produce chips having said predetermined fiber length regardless of the instantaneous speed of the carriage.

4. Apparatus as claimed in claim 3 in which the means for moving the chipper unit and head selectively moves said head anywhere from a position on the same side of the new plane as the carriage to a position on the opposite side and clear of said plane.

5. Apparatus for chipping and sawing logs comprising, in combination, a head saw operable in a saw plane, a carriage mounted for reciprocal movement along a path outwardly of the saw plane and past the saw, clamping means on the carriage for firmly retaining a longitudinally extending log thereon with a portion of a side of the log projecting laterally from the carriage into said saw plane, said gripping means gripping the log throughout substantially the length thereof and on the side of the log remote from said saw, power means connected to the carriage operable to cause said carriage to reciprocate past the saw to enable the latter to cut a board from the log, a chipper head mounted on a base on the same side of the carriage and the saw and movable towards and away from the carriage path, blades on said chipper head adapted to cut chips from the projecting portion of a log on the carriage during movement of the carriage in the direction of the saw, power means on said base connected to rotate the chipper head, control means for causing the carriage to reciprocate past the head saw and the chipper head, said control means including means for stopping and starting the carriage at the end of each run and a first varying means for varying the speed of the carriage during each run, means for constantly sensing the speed of the carriage and instantly changing the speed of rotation of the chipper head in accordance with changes in the carriage speed, and a second varying means for varying the speed of rotation of the chipper head, and means for selectively shifting said base to move the chipper head in a direction substantially normal to the saw plane to shift said head to various positions relative to said plane, wherein said first and second varying means are coordinated with each other through the said sensing means to produce chips having said predetermined fiber length regardless of the instantaneous speed of the carriage.

6. Apparatus as claimed in claim 5 in which said means for shifting the base selectively moves the chipper head anywhere from a position outwardly of the saw plane to a position on the opposite side of said plane clear of the log on the carriage.

7. Apparatus as claimed in claim 5 in which said base is slidably mounted on rails extending normal to the carriage path, and said shifting means also is mounted on said rails.

8. Apparatus as claimed in claim 7 including means releasably securing said shifting means on the rails, said securing means being releasable to permit said shifting means and said base with the chipper head thereon to be moved away from the carriage path.

9. Apparatus as claimed in claim 5 including hood means at the chipper head and adapted to direct chips cut by the head blades away therefrom.

10. Apparatus as claimed in claim 9 in which said hood means directs the chips away from the chipper head, and in cluding a chute positioned to receive the chips from said hood and to direct the chips away from the apparatus.

11. Apparatus as claimed in claim 5 including setworks connected to the base for moving the latter into different selected positions relative to the carriage path,

12. Apparatus as claimed in claim 5 including means on the carriage for shifting the gripping means and the log gripped thereby towards and away from said saw plane. 

1. Apparatus for chipping and sawing logs comprising, in combination, a head saw, a sawmill carriage mounted for movement past the saw, gripping means on the carriage for holding a log extending longitudinally thereof in order that a board can be cut therefrom when the carriage moves past the saw, a chipper unit mounted near the path of travel of the carriage for movement towards and away from said path, a chipper head on the unit on the same side of the carriage as the head saw and positioned and adapted to cut into chips having a predetermined fiber length the side of the log on the carriage as the latter moves in the direction of the saw, means for selectively moving the chipper unit in a direction substantially normal to the plane in which the saw is located to shift the head to various positions relative to said plane, manually operable first control means for controlling the speed of the carriage in accordance with sawing conditions, second control means for regulating the speed of rotation of the cutting head, means for constantly sensing the speed of the carriage and operably connected to said second control means for instantly changing the speed of rotation of the chipper head in accordance with changes in the carriage speed, whereby chips are produced having said predetermined fiber length regarDless of carriage speed changes during movement thereof.
 2. Apparatus as claimed in claim 1 in which the means for moving the chipper unit and head selectively moves said head anywhere from a position on the same side of the saw plane as the carriage to a position on the opposite side and clear of said plane.
 3. Apparatus for chipping and sawing logs comprising, in combination, a head saw, a sawmill carriage mounted for movement past the saw, gripping means on the carriage for holding a log resting on and extending longitudinally of the carriage in order that a board can be cut therefrom when the carriage moves past the saw, said gripping means gripping the log throughout substantially the length thereof and on the side of the log remote from said saw, a chipper unit mounted near the path of travel of the carriage for movement towards and away from said path, a chipper head on the unit on the same side of the carriage as the head saw and positioned and adapted to cut into chips having a predetermined fiber length the side of the log on the carriage as the latter moves in the direction of the saw, control means for causing the carriage to reciprocate past the head saw and the chipper head, said control means including means for stopping and starting the carriage at the end of each run and a first varying means for varying the speed of the carriage during each run, second varying means for varying the speed of rotation of the chipper head, means for constantly sensing the speed of the carriage operatively connected to said second varying means instantly to change the speed of rotation of the chipper head in accordance with changes in the carriage speed during movement thereof, and means for selectively moving the chipper unit in a direction substantially normal to the plane in which the same is located to shift the head to various positions relative to said plane, wherein said first and second varying means are coordinated with each other through the said sensing means to produce chips having said predetermined fiber length regardless of the instantaneous speed of the carriage.
 4. Apparatus as claimed in claim 3 in which the means for moving the chipper unit and head selectively moves said head anywhere from a position on the same side of the new plane as the carriage to a position on the opposite side and clear of said plane.
 5. Apparatus for chipping and sawing logs comprising, in combination, a head saw operable in a saw plane, a carriage mounted for reciprocal movement along a path outwardly of the saw plane and past the saw, clamping means on the carriage for firmly retaining a longitudinally extending log thereon with a portion of a side of the log projecting laterally from the carriage into said saw plane, said gripping means gripping the log throughout substantially the length thereof and on the side of the log remote from said saw, power means connected to the carriage operable to cause said carriage to reciprocate past the saw to enable the latter to cut a board from the log, a chipper head mounted on a base on the same side of the carriage and the saw and movable towards and away from the carriage path, blades on said chipper head adapted to cut chips from the projecting portion of a log on the carriage during movement of the carriage in the direction of the saw, power means on said base connected to rotate the chipper head, control means for causing the carriage to reciprocate past the head saw and the chipper head, said control means including means for stopping and starting the carriage at the end of each run and a first varying means for varying the speed of the carriage during each run, means for constantly sensing the speed of the carriage and instantly changing the speed of rotation of the chipper head in accordance with changes in the carriage speed, and a second varying means for varying the speed of rotation of the chipper head, and means for selectively shifting said base to move the chipper head in a direction substantially normal to the saw plane tO shift said head to various positions relative to said plane, wherein said first and second varying means are coordinated with each other through the said sensing means to produce chips having said predetermined fiber length regardless of the instantaneous speed of the carriage.
 6. Apparatus as claimed in claim 5 in which said means for shifting the base selectively moves the chipper head anywhere from a position outwardly of the saw plane to a position on the opposite side of said plane clear of the log on the carriage.
 7. Apparatus as claimed in claim 5 in which said base is slidably mounted on rails extending normal to the carriage path, and said shifting means also is mounted on said rails.
 8. Apparatus as claimed in claim 7 including means releasably securing said shifting means on the rails, said securing means being releasable to permit said shifting means and said base with the chipper head thereon to be moved away from the carriage path.
 9. Apparatus as claimed in claim 5 including hood means at the chipper head and adapted to direct chips cut by the head blades away therefrom.
 10. Apparatus as claimed in claim 9 in which said hood means directs the chips away from the chipper head, and including a chute positioned to receive the chips from said hood and to direct the chips away from the apparatus.
 11. Apparatus as claimed in claim 5 including setworks connected to the base for moving the latter into different selected positions relative to the carriage path.
 12. Apparatus as claimed in claim 5 including means on the carriage for shifting the gripping means and the log gripped thereby towards and away from said saw plane. 